Nos tutelles

Rechercher

Nucleation & growth of nanomaterials in liquid phase

publié le 2 janvier 2018, mis à jour le 11 janvier 2018

Liquid-phase syntheses are very versatile methods to fabricate complex nanomaterials with controlled size, shape and atomic structure. However, because of the lack of efficient tool to visualize nano-object dynamics in liquids, the theories on the nucleation and growth mechanisms remain mostly speculative and sometime contradictory. For a long time, this bottleneck has favored the use of empirical approaches to improve synthesis protocols. To address this fundamental issue, the MPQ Lab has been the first laboratory in France to exploit liquid-cell TEM with the view to provide in situ insights on the formation mechanisms of anisotropic gold nanoparticles and bimetallic nanostructures. Remarkably, this technique allows distinguishing kinetic effects that depends on the growth speed and thermodynamic effects dictated by the stability of nanomaterials within its environment. Therefore, we can take a fresh look at many strategies employed by colloidal chemists to control the size and shape of nanostructures, including seed-mediated synthesis, functionalization methods, kinetically-controlled growth, but also chemical etching and galvanic replacement. These mechanistic information open up the unique opportunity to confirm existing theory or to reveal surprising growth processes, so that we can gain control over the fabrication of nanomaterials and design more sophisticated nano-architectures.